U.S. Pat. No. 3,792,850 describes such a device. The tilting runner comprises a supporting cradle, which is supported with the assistance of two supporting trunnions so as to be capable of tilting about a horizontal tilt axis and a runner element with two opposing discharge spouts which is positioned interchangeably in the supporting cradle. A supporting cradle drive unit comprises a motor reducer unit with a crank. This crank is connected via a connecting rod to a lever arm of the supporting cradle.
Document KR20040046395 discloses a tilting runner in which the motor reducer unit is coupled, without an intermediate connecting rod/crank, to one of the two trunnions of the supporting cradle.
A drawback shared by these two tilt mechanisms with a motor reducer unit is that, given the large weight of the tilting runner, the levels of torque output by the reducer must be relatively high, which entails a large and therefore costly motor reducer unit. One advantage of a drive unit with a motor reducer unit resides in the fact it is possible to provide the reducer with a second input shaft connected to a hand wheel which makes it possible to tilt the tilting runner manually in the event of a problem with the motor of the motor reducer unit or with its power supply. However, this second input shaft entails an additional gear train with a very high transmission ratio to allow the tilting runner to be tilted manually, so still further increasing the cost of the motor reducer unit.
There are also tilting runners which have a supporting cradle drive unit which comprises a hydraulic or pneumatic piston-cylinder unit connected to a lever arm of the supporting cradle. However, a hydraulic piston-cylinder unit of large diameter, which requires elevated flow rates of hydraulic oil under high pressure to function, is inadvisable in the immediate vicinity of large quantities of liquid iron (fire hazard). A pneumatic piston-cylinder unit, on the other hand, has the disadvantage of not permitting reliable adjustment of the angle of inclination of the tilting runner. Furthermore, the solutions with a hydraulic or pneumatic piston-cylinder unit have the disadvantage of not providing the possibility of manually tilting the tilting runner in the event of a problem with the supply of hydraulic or pneumatic fluid.